---

作 者 ：杨秀清,,韩有志*,,李乐,,陈欣,,游静

期 刊 ：生态学报 2009年 29卷 9期 页码：4656~4664

关键词：华北落叶松；更新格局；土壤氮素；异质性；空间关联性；

Keywords:Larix principis\|rupprechtii, regeneration pattern, soil nitrogen, heterogeneity, spatial relevance,

摘 要 ：在华北山地典型天然次生林中选择研究样地，应用地统计学理论和格局分析方法，定量分析林分土壤氮素空间异质性特征，探测更新幼苗空间格局特征；依据协同变异函数理论模型参数，定量估计土壤氮素营养空间异质性与落叶松更新格局之间的空间关联性，探讨土壤氮素空间变异对落叶松幼苗更新格局的影响程度。研究结果表明：(1）无论是以华北落叶松为优势树种的寒温性针叶林，还是以白桦和山杨为优势树种的山地阔叶林，不同空间样点间土壤氮素总量及速效态氮素均存在很大差异。阔叶林中，硝态氮在整个研究样地尺度（＞70.71m）上表现出很强的空间自相关性（结构因素所占比重为81.5%）。针叶林中，硝态氮则在相对小的尺度范围（47.90m）呈现更明显的空间自相关变异。且阔叶林中土壤氮含量显著地高于针叶林。(2）华北落叶松苗更新空间分布格局呈明显的集聚分布。更新的空间格局变异主要由空间自相关因素引起（针叶林为77.4%，阔叶林为85.2%），随机变异占的比例较低（分别为22.6%和14.8%）。(3）阔叶林土壤氮含量相对高，更新与氮素的空间关联性不明显，与全氮的协同变异呈随机性（R2=0.078）。针叶林土壤氮含量相对低，更新与氮素的空间关联性明显，与全氮的协同变异呈现明显的空间自相关性，氮素空间异质性对更新格局与过程具有更重要的影响。整个研究样地水平上，硝态氮与更新的协同变异呈现明显的空间自相关性（空间结构比为59.4%～77.7%）。NO-3\|N含量较高或铵、硝态氮的比例较低的土壤环境中，更新苗发生数量较多。

Abstract:By geostatistic and pattern analysis, we quantified heterogeneous spatial distribution of soil nitrogen and studied pattern characteristics of regenerated Larix principis\|rupprechtii seedlings in typical naturally\|regenerated montane forests of Northen China. Using methods of covariance parameter analysis, the relation was determined between spatial distribution of soil nitrogen and regeneration pattern of the seedlings. Results showed both total and available nitrogen concentration were significantly different in different quadrats for both Larix principis\|rupprechtii dominated boreal\|temperate conifer forest and Betula platyphylla\|Populus davidiana dominated montane broad\|leaved forest. In the broad\|leaved stands, NO-3\|N was strongly auto\|correlated with the entire research spatial range (＞70.71m), where the spatial structure accounted for 815% of total variance. However, in the conifer stands, where the soil nitrogen content was significantly lower than that of broad\|leaved stand, NO-3\|N was significantly auto\|correlated with a relatively small range (47.90m). Regeneration pattern of Larix principis\|rupprechtii seedlings was gathering distribution. The spatial heterogeneity in regeneration pattern was mainly caused by spatial auto\|correlative factors (77.4% in conifer stand and 85.2% in broad\|leaved stand), and the effects of random factors (22.6% and 14.8% respectively) were minor. Because soil nitrogen content was relatively high in broad\|leaved stands, the relevance between regeneration and spatial nitrogen distribution was not significant and the covariance between regeneration and total nitrogen was random (R2=0.078). However, in conifer stands, due to relatively low soil nitrogen content, the covariance between regeneration and total nitrogen was generally auto\|correlated, and the impact of heterogeneous spatial distribution of soil nitrogen on regeneration pattern and process was more significant. Covariance between regeneration and NO-3\|N was spatially auto\|correlated with spatial structure accounting for 59.4%-77.7% of total variance. Regenerated seedlings was generally more in soils with higher NO-3\|N concentration or lower rate of NH+4\|N / NO-3\|N.

---